Thrombocytopenia is a significant problem in the treatment of cancer.

To assess the clinical safety of therapy with recombinant human thrombopoietin (rhTPO) and its ability to ameliorate chemotherapy-induced severe thrombocytopenia.

Phase I/II clinical cohort study.

The University of Texas M.D. Anderson Cancer Center, Houston, Texas.

29 patients with gynecologic cancer.

Recombinant human thrombopoietin was given before chemotherapy and after a second cycle of carboplatin therapy.

Peripheral blood counts and platelet transfusions.

Administration of rhTPO after chemotherapy significantly reduced the degree and duration of thrombocytopenia and enhanced platelet recovery. In patients who received the optimal biological dose of rhTPO (1.2 µg/kg of body weight) in cycle 2 (carboplatin plus rhTPO), the mean platelet count nadir was higher (44 × 10⁹ cells/L and 20 × 10⁹ cells/L; P = 0.002) and the duration of thrombocytopenia was shorter (days with a platelet count <20 × 10⁹ cells/L, 1 and 4 [P = 0.002]; days with a platelet count <50 × 10⁹ cells/L, 4 and 7 [P = 0.006]) than in cycle 1 (carboplatin only). The need for platelet transfusion in this group was reduced from 75% of patients in cycle 1 to 25% of patients in cycle 2 (P = 0.013).

Therapy with rhTPO seems to be safe and may attenuate chemotherapy-induced severe thrombocytopenia and reduce the need for platelet transfusions.